Purpose. The «KOF surprise indicator» was slightly revised in order to improve its coverage of Swiss economic developments. To that aim firms that report local or regional activity only had to be removed from the sample.

Results. The revised indicator shows a strong correlation with its predecessor of 98 percent. The revised «KOF surprise indicator» also exhibits a slightly higher correlation with the Swiss GDP (year-on-year change of quarterly GDP), up from 87 to 90 per cent.
The old and the revised indicator values are plotted in the figure below. It demonstrates the unique, strong co-movement of the «KOF surprise indicator» and Swiss real GDP.

Conclusion. In view of these revision results it remains safe to conclude that the «KOF surprise indicator» provides a reliable anchor even if revised.